"Until yesterday, there were 4 different variations of the Aqua theme used by Apple for OS X: the standard Aqua theme, the new Platinum theme, the much distained Brushed Metal theme, and the funky Woody theme. Commentators have pointed out on more then one occasion that while Apple's Human Interface Guidelines has guidelines for which theme to use where, even Apple disregards those rules and uses whatever theme some unknown source in the company chooses."